I bought my 85 with 107,000 original miles last week. Upon inspection realized p/o was not into preventative maintenance what so ever. After sealing the exhaust it starting running rough. At this point I replaced the o2 sensor and set the timing, it did nothing sounded like it was running on 3 cylinders. Mind you I had to drive it 600 miles home and it performed flawlessly. I decided to take it to toyota and have the compression checked, came back #2 cylinder is at 60psi while the others are all above 120. My question is should I remove head have it rebuilt, and is there a way to check rings without removing them. There is no oil in coolant and seems to be no smoke. Again truck has 107,000 miles and has never seen the dirt once but the p/o was a cheap douch.

 

It can always be rebuilt. I'd pull the head and take a look around.